PVC is polyvinyl chloride, the main amorphous material as a raw material, is divided into two types of soft and hard, respectively for different use occasions to provide different choices. Soft PVC is often used as a surface material for floors and ceilings, while hard PVC materials are more widely used in corrugated panels, door and window structures, and various chemical industry manufacturing. And PVC material also has changeability, by adding different additives, can change its physical properties and mechanical properties, can cope with different use occasions.
PVC material not only has the advantages of corrosion resistance, non-flammable, insulation, oxidation resistance, etc., but also because of its reprocessing and low production costs, it has always maintained high sales in the material market. This is also due to its wide range of uses and affordable price. At present, the improvement and design technology of PVC materials in China has reached the international advanced level.
Major hazard
Polyvinyl chloride is composed of polyvinyl chloride resin, plasticizer and antioxidant resin, itself is not toxic. However, the added plasticizer, antioxidant and other auxiliary materials are toxic, the plasticizer in PVC plastics for daily use mainly uses dibutyl terephthalate, dioctyl phthalate, etc. These chemicals are toxic, and the antioxidant lead stearate of PVC is also toxic. Polyvinyl chloride products containing lead-salt antioxidants will precipitate lead when they come into contact with ethanol, ether and other solvents. Polyvinyl chloride containing lead salt is used as food packaging and fritters, fried cakes, fried fish, cooked meat products, cakes and snacks, which will cause lead molecules to spread to the grease, so you can not use polyvinyl chloride plastic bags to contain food, especially oily food. In addition, polyvinyl chloride plastic products will slowly decompose hydrogen chloride gas at a high temperature of about 50 ° C, which is harmful to the human body, so polyvinyl chloride products should not be used as food packaging.
Since most of the disposable medical device products use medical grade polyvinyl chloride (PVC) or polycarbonate (PC), and the thermal decomposition of PVC processing has a strong corrosion of steel, PC is high hardness and viscosity, so the material requirements of the plasticized part of the parts must be able to resist corrosion, wear resistance and have high polishing performance. In addition, in order to prevent the production of gas during the thermal decomposition of PVC processing, the surface of the movable fixed template is required to be aluminized, and the outer sheet metal is also aluminized or made of stainless steel plate, and the sheet metal joint is sealed with non-toxic silicone. To prevent the gas generated in the plastic processing process from running outside (the gas generated in the plastic processing process can be collected centrally through special equipment and then purified before being discharged into the atmosphere).
In the case of a large number of demands, it is easy to appear mixed, uneven quality phenomenon. Especially when ordinary users buy PVC materials themselves, they are often easy to be fooled by the black-hearted boss of small shops. The performance of inferior PVC materials in wear resistance and pollution resistance is far less than that of good quality PVC materials. Products made of inferior PVC are not only functionally poor, but also have a very short service life. Therefore, when you buy PVC materials by yourself, you must go to the relevant specialty stores to buy.